Advanced Materials Research Vols. 356-360

Abstract: Though the suggestions on health risk assessment of extremely low frequency (ELF) electric and magnetic fields (EMF) by WHO has gradually begun to spread relative effectively among the administrative departments of environmental protection in China, there are still individual media or experts calling for reducing exposure limits to the arbitrary low level in the name of precaution, and endeavoring to affect the government to make decisions or management policies on EMF, with the purpose for their own interest. It has been leading to the increasing anxiety and fear towards EMF of general public. Based on the current status of EMF issue and standard development in China, this paper analyzes the principles of precautionary policies and related precautionary measures on EMF worldwide in combination with the result of risk assessment on ELF EMF and the suggestions for standards on exposure limits by international organizations, and comprehensively considers the practical situation of power transmission and transformation projects to put forward the recommendations. The exposure limits provided in the guidelines or standards by international organizations, such as International Commission on Non-Ionizing Radiation Protection (ICNIRP) and Institute of Electrical and Electronic Engineers (IEEE), is safe enough to protect the health of general public. And for power transmission and transformation projects, the basic restrictions are the essential limits in these guidelines or standards, while the reference levels are just easier to implement in practical for guidance. The set of criteria for precautionary principle provided by European Union could be regarded as the reference for the development principle of precautionary policy, involving proportionality, non-discrimination, consistency, examination of the benefits and costs, examination of scientific developments and so on. Since in fact the EMF by power transmission and transformation projects belongs to weak risk, the core of precautionary policies lies in being no or low cost in practical, especially for new electrical equipments.

Abstract: Accident is undesired to anyone. But the research shows that the main cause of accident is unsafe behavior. The interaction mechanism of accident system was analyzed in the process of gas explosion through typical accidents and the conclusion was that the accident was occurred because unsafe behavior induced the dangerous factor in work environment. In order to further acquaint of it, the situation cognition of workers in the coal mine production process was analyzed with the research of aviation. The cognition of safe information in work process was affected by workload, goal, work habituation and others. As workload increased, goal strengthened, the attention apperceived safe information is weaken and the major change of safe information wasn’t apperceived immediately in work environment, and the accident was happened in conditions of unsafe behavior. Finally, the accident model based on situation cognition was posed and some measures were proposed.

Abstract: Exposure to biogenic aerosols such as airborne bacterium has hazardous effects upon human health. Mycobacterium tuberculosis (MTB) bacteria is a highly pathogenic microbe and arises large challenges to the enclosed laboratories for biosafety and the health of people working in them. Number concentration and size spectra of indoor aerosols were examined in the Animal Biosafety Level 3 (ABSL-3) laboratory located in Shanghai’s south suburb in July 2010. Mean particle concentration at center of the core room in dissecting experiment to MTB infected mouse (200 cm^-3) was equivalent to feeding experiment to MTB infected mouse (200 cm^-3), and roughly 2 times higher than background (91 cm^-3). Mean particle size distribution at center of the core room exhibited a bi-peak feature under dissecting and feeding conditions, but a mono-peak feature under background condition. Because of dual negative air pressure and high frequency cleaning, MTB bacteria emitted from infected agents did not appear in the air of the preparation and core rooms. Airborne particle sampling demonstrated that MTB aerosol contamination was not detected in the indoor air. This result indicates that online monitoring for particle microphysical properties is one valuable approach to early warn and protect the safety of ABSL-3 laboratories.

Abstract: Eleven chlorpyrifos-degrading bacterium were isolated from a Chinese soil and compared by microbiological and molecular methods. The strains were significantly different in the ability of degradation efficiency, and one strain (Bacillus cereus) was selected for further analysis. The ability of Bacillus cereus to degrade chlorpyrifos was investigated under different culture conditions, such as pH, temperature, chlorpyrifos concentration and so on. Experimental results obtained in different conditions show that the optimum temperature, pH, concentration of chlorpyrifos were 30°C, 7.0, less than 100 mg L^-1, respectively.

Abstract: Organotin compounds are high toxiferous chemicals and ubiquitous in our environment, which also have high biological activities. Di-n-butyl-(4-chlorobenzohydroxamato)tin (IV) chloride (DBDCT) represents a new paradigm for tin-based antitumor complexes with high activity. The inhibitory effect of DBDCT on cytochrome P450 3A(CYP3A) was studied in this article. The adult male SD rats were randomly divided into five groups with six in each and treated separately with saline, lipopolysaccharide (LPS, 5mg/kg), DBDCT (1.25, 2.5 and 5.0mg/kg, respectively) intraperitoneally for 2 days after induced with dexamethasone (DEX) at a dose of 100mg/kg for 4 days. The cytochrome P450 (CYP450) content was assayed by the method of Omura and Santa after the protein concentration detected by BCA assay kit. The activity of CYP3A was determined by the method of Nash. Western blot analysis was used to detect the expression of CYP3A1/2 at protein level in rat liver microsomes and Buffalo Rat Liver (BRL) cells. The results demonstrated that the activity of CYP450 and CYP3A were inhibited by exposure to DBDCT in rat liver compared with that of the blank control group. The expression of CYP3A1 and CYP3A2 proteins in rats treated with 1.25, 2.5 and 5.0mg/kg DBDCT were down-regulated respectively by 22.8% (p<0.01),24.3%(p<0.01), 58.4%(p<0.001) and 37.6%(p<0.001), 41.4%(p<0.001), 49.2%(p<0.001), than that of the blank control group. Immunoblot analysis of protein from BRL cell lysate demonstrated that the expression of CYP3A1 and CYP3A2 protein reduced separately by 11.4% (p<0.05), 34.2%(p<0.001), 45.5%(p<0.001), 64.9%(p<0.001), 78.8%(p<0.001) and 12.8% (p<0.05), 9.9% (p<0.05), 28.0% (p<0.001), 24.9% (p<0.001), 34.2% (p<0.001) after treated with DBDCT at a dose of 1µmol/L (for 24, 36, 48h) and 2µmol/L(for 24 and 48h). The activity of CYP3A in rat liver microsomes was decreased remarkably compared with that of the blank control group. Immunoblot analysis showed that the expression of CYP3A1/2 was inhibited significantly by DBDCT in rat liver and BRL cells.

Abstract: The dam break accidents of the tailings ponds occur from time to time, which has a serious threat to people's properties and lives. This paper uses the 3S technologies combined with conventional monitoring technology to build intuitive, real-time, and dynamic online monitoring network system for the observation, analysis, and early warning of the tailings ponds. When the monitoring data are abnormal, the system alarms to the personnel who manages the tailings pond by dual-mode method of sound and light. Meanwhile, the warning site is visually shown by the words and illustrations. The system provides a strong technical support for the safety supervision, accident prevention, and accident pre-control of the tailings ponds.

Abstract: Determination of main impact factors of river health is important to river management, ecological rehabilitation and construction. Based on the definition of river health in China, the factors were divided into two categories, that is, endogenous factors and exogenous factors. The method used to main impact factor analysis was suggested which is based on the relation between the factors and the partial least squares regression. The model was applied to analyze main impact factors of river health of the lancun-Yitang reach in the middle Fenhe River. The result shows that the proposed model can reflect the actual situation.

Abstract: Palygorskite is widely used as industrial adsorbent and also potential for flue gas desulfurization by adsorption of SO₂. The effect of thermal treatment on Palygorskite’s structural properties and its performance in SO₂ adsorption were investigated. The textural and structural properties of the prepared palygorskite adsorbent were characterized by X-ray diffraction, transmission electron microscopy and temperature programmed desorption. The result showed the channel of Palygorskite is partial collapsed and the structure is not changed ultimately when thermally treated below 300 °C. The structure of Palygorskite is Gradually changed when the treating temperature is higher than 300 °C and is damaged entirety till 800 °C. As a result, the adsorption capacity of SO₂ on Palygorskite decreased drastically. It is suggested that the presences of surface adorbed water and zeolitic water which occupy a large number of adsorption sites are disadvantage for the adsorption of SO₂, and dissimilarly the presence of crystal-bonded water is favorable.

Abstract: The adsorption of hydrogen sulfide (H₂S), carbondioxide (CO₂) and methane (CH₄) on H-FER zeolite was investigated under computational chemistry using ONIOM (HF/6-31G (d,p):UFF) and ONIOM (B3LYP/6-31G (d,p):UFF) method. Compared to the H-FER zeolite induces much stronger binding of H₂S, CO₂ and CH₄ suggesting great enhancements in the adsorption selectivity. The order of binding energies of adsorbed molecules is H₂S > CO₂ > CH₄. It was found that the extended zeolitic framework covering the nanocavity was essential for describing the confinement effect of the zeolite. The results of these calculations show that the zeolite can be used to adsorb H₂S bester then CO₂ and CH₄. Carbondioxide and hydrogen sulfide are pollutant in biogas product from anaerobic digestion of biodegradable materials. There for, zeolite can be use to purified gas before using as fuel.

Abstract: Dry deposition and wet remove of sulfur from main power plants plan to build in Henan province of China were numerically simulated with CALPUFF based on estimated SO₂ emissions of each plant. The results of simulation shows that, the highest grid point annual dry deposition and wet remove quantity of sulfur from power plants reaches 554.498kg/km² and 457.745kg/km² respectively. Annual dry deposition and wet remove of sulfur in Henan region can reaches to 8381.422 ton and 4974.747 ton respectively. Zhengzhou was the most heavily impacted city by dry deposition and wet remove of sulfur from power plants, and annual flux of dry deposition and wet remove can reach to 366.953kg/km² and 188.743kg/km2 respectively. After the completion of construction of new plants and the closing down of old ones, dry and wet deposition in most region of Henan ^{Superscript text}province declined, and 4642.220 ton of dry deposition and 2405.216 ton of wet deposition were lessened annually according to the simulation.